Robin van Persie has issued an ominous warning to Braga as the Manchester United forward claimed his partnership with Wayne Rooney is finally beginning to live up to expectations.

Robin van Persie has issued an ominous warning to Braga as the Manchester United forward claimed his partnership with Wayne Rooney is finally beginning to live up to expectations.

Braga have the daunting task of trying to subdue two of Europe's finest frontmen when the Portuguese minnows visit Old Trafford for Tuesday's Champions League Group H clash.

But to make matters worse for Braga, van Persie, who has eight goals in 10 appearances for United, believes his understanding with Rooney has gradually clicked into gear after a slow start following his pre-season move from Arsenal.

Van Persie's lack of match practice and an injury to Rooney meant the pair have played together only fleetingly in the opening weeks of the season.

They are finally getting some prolonged time on the pitch to work on their relationship and the response has been impressive, as Stoke found out on Saturday when Rooney scored twice and van Persie also netted in a 4-2 win.

The deadly duo were also responsible for three of the four assists against Stoke and Braga's defenders could have been forgiven for cursing their luck as van Persie described the rapid development of United's strikeforce.

"We are definitely getting more of an understanding," Van Persie said. "We like to play together and work well together.

"It is only the second or third time we have played in this formation but offensively and defensively, we help each other out."

With Danny Welbeck also a growing threat up front and Javier Hernandez, Nani, Shinji Kagawa and Ashley Young also offering their own attacking menace, it is no surprise van Persie expects United to produce a glut of goals as the season continues.

"We do look exciting going forward. We can score all sorts of goals from many different angles," he said. "That is a good sign and should be a real weapon for us as the season goes on."

While United are in rampant form going forward, van Persie admits they must tighten up at the back after Rooney's own goal on Saturday left them trailing for the seventh time in 11 matches this season.

It is a run that has already cost Alex Ferguson's side valuable points against Everton and Tottenham and van Persie said: "It has happened too often. We have to work on it because we can only do better."

United's defensive woes mean Ferguson may think twice before dropping Rio Ferdinand, who angered the Scot by ignoring his request that all of his players show support for the Kick It Out anti-racism campaign by wearing the equality group's t-shirts during the pre-match warm-up before the Stoke game.

Ferdinand, angry at what he perceived to be a weak punishment of Chelsea defender John Terry for racially abusing the United star's brother Anton last year, refused to wear the t-shirt and Ferguson responded by saying the veteran centre-back would be "dealt with".

With or without Ferdinand, United should extend their 100 percent start to the Champions League group stage with another success after their victories over Galatasaray and CFR Cluj.

Ferguson won't take Braga for granted however as they won 2-0 at Galatasaray in their last group fixture and are currently on a five-match unbeaten run against English opposition.

"Traditionally there have always been three teams in Portugal, Sporting Lisbon, who have dropped off a bit at the moment, Porto and Benfica," Ferguson said.

"But now Braga have become the third best team in Portugal. They drew 2-2 at Benfica, played really well and should have won.

"I spoke to (United's Portugal winger) Nani, who said they are very positive away from home.

"I saw that in the Benfica game, so we won't be taking anything for granted."